I sometimes question the validity of the notion that the Golden Ratio is somehow the basis of beauty. To me, it seems to be something of a remnant of the rationalism of the 17th century that really ought to have passed away when empiricism became prevalent later. I find beauty in assymetry, a face which is too "perfect" puts me off. It looks strange and inhuman, somehow unnatural. People's flaws are as much a part of their beauty as anything else, and a flawless face which perfectly corresponds to some mathematical formulation of beauty just looks boring.
The story told by Brian Sewell about Salvador Dali that he once ejaculated on the spot on seeing a nude youth emerging from the sea having cut his foot on a rock, with blood spilling into the water, reminds me that the beholder can find the most extreme beauty in almost anything. Many find beauty in ugliness; and I think that if it were true that we are instinctively drawn to one particular ratio, there would be far less variation in what people find attractive.
Re: Beauty and its relation to finding a mate.
I don't think that this is the purpose of our perception of beauty; rather, I say it has its instinctive roots in our need to find food and shelter. What we find beautiful in other people is specific to culture, I maintain, and to the individual - the reason for this, I think, is because when we see beauty in anything other than an environment, it is by analogy to our instinctive notion of environmental beauty that the thing is beautiful; i.e. a beautiful person is beautiful because their features are reminiscent of 'bounty' - and, being human, our notion of what constitutes 'bounty' is based on cultural awareness rather than on instinct.
We are far less picky about beauty than about other things when it comes to finding a mate, I think. While people do tend to be superficial at first, ultimately I think much of this is bluster and bravado - it's a form of competition. Because we share cultural awareness with others of our culture, and because we instinctively desire to possess what we perceive as beautiful (let me be clear here, what I'm saying is that beauty is what indicates plentiful resources in nature), we like to suggest to potential competitors that we could, if we wanted, possess a beautiful partner. What we keep to ourselves, or what we are not even aware of, is that we are often attracted, in mates, to something quite other than the conventional notion of beauty. That smell factors into the equation a great deal is significant - we do not look for beautiful smells, but for smells which indicate virility or femininty (i.e. smells which are rich in all the right pheromones), and therefore ability to reproduce. We also look for genetic variation, since a partner with genes very different from our own is more likely to produce healthy offspring. Thus, our assertions that we desire partners who possess the conventional image of beauty is an effort to convince potential mates of our own strength and dominance: we are saying that we can have what we want, we can have beautiful - and therefore, bountiful - things.
Additionally, I think that the theory that we select a mate on the basis that we can develop a strong bond with them is also invalid. Kinship is a cultural phenomenon, not an instinctive one; that is to say, it is not intrinsic to human nature that a child has a mother and a father. That is a peculiarity of our own kinship structure, which we defend using the ideology of science. There is a biological fact that the child has the genetic information of both parents, yes; but this is as valid a grounds for kinship as any. Children may have been communally raised in many early societies, where too much time had to be invested in the production of food for a healthy, fit individual of either sex to expend time and effort bringing up a child - rather, that duty would probably fall upon those too old or infirm to do anything else. This raises questions over what the biological purpose of love is. I think that it is not so much a matter of guaranteeing that the child will be raised successfully (after all, the chances are that it will die in infancy anyway), but rather that as soon as one pregnancy is over, another can begin - i.e. it is a mechanism by which a breeding pair, once they have found eachother, guarantee the continued production of offspring; largely so that when the first eight die there are another eleven on the go anyway. At the same time, I would stress that polyamory is perfectly possible, and alternative structures, where several mating partners are bound to eachother, are not only possible but, in fact, more efficient than breeding pairs - if one member of that structure dies, it does not really matter. We see this in some ancient societies - in Mesopotamia, Greece and Rome it was considered acceptable for a man to have sex with whatever woman (or man) he wanted, so long as she was not married to another man - marriage was a contract to ensure the inheritance of an estate, and was not otherwise related to reproduction.
